Our estimate was the panels broke even after 8 years; we've been here for 9 so it should be profit territory by now. I think we paid nearly ¥2,000,000 for ours, which were the latest-and-greatest at that moment. Our house is all electric, so Spring and Fall we usually break even on the power bill -- half the year is "free."
In the USA, my sister has solar, and it seems like the government-sponsored private industries are involved in all manner of fuckery so they can maximize their profits even if it slows the uptake away from fossil fuel consumption. It's ridiculous.
Since the US government and private industry seems to drag their feet so badly, I keep wanting the Native Americans to install massive solar farms on their land and start selling power back out to the world.